Have a new construction home in Florida (CBS construction) I am inspecting. Home owner using SPF closed cell spray insulation in attic. Areas over arch windows are frame with plywood both sides. I have a 2 part question:
1st- Can closed cell insulation be shot in the small frame cavity (picture below). One insulation contractor says yes the other says no due to expansion of closed cell insulation will destroy framing.
2nd part: If closed cell cannot be used can open cell be used?
I have researched but cannot find a conclusive answer…any help would be appreciated thank you
If the installer knows what he is doing, then it shouldn’t be a problem. Unless the applicator keeps pumping the insulation for an hour, I doubt it will cause the framing to fail.I would recommend you go with the guy who said to do it.
I got this answer from Icynene tech support. They explained that there is several types of density and expansion properties to different products they manufacture. There are low density, decreased expansion products that are used in retro-fitting situations and this type of application where expansion properties would need to be limited do to the enclosed area.
Unless there are large, I mean large, holes to allow for expansion, I would fill that area with fiberglass. When I was building in Texas, one of the superintendents used foam from a can to insulate a window arch because the inspector discovered it was not insulated and failed the inspection. I got there just after the inspector the next day and he was laughing as I walked into the home. The framing blew out on both sides. Whole thing had to be torn out and reframed.
Agree with Eric above. If the installer knows what he is doing, it’s not a problem. Of course, that assumes that the installer is a qualified professional, as he would be aware of the info in Fred’s post.